Known in the art is a system for automatic sampling and slurry sample conveyance for analysis (cf. Yanchevsky V. N. et al., System for Conveying Slurry Samples for Analysis in a Quantometer KRF-13. (in Russian), Innovative Proposals and Inventions, No. 6, (342), pp. 8-10, Moscow, 1980), comprising samplers installed on slurry lines conveying products being analyzed, a sampling member of a slurry sampler being connected to a receiving sump of a rotary pump by means of a flexible hose. The pump, in the analysis mode, pumps in the sample through a conveying line to a pressure tank which is installed in an express laboratory over the cells of an analyzer. The receiving sump of the pump has a check drain funnel, and the flexible hose of the sampler is connected to a pneumatic membrane actuator by means of a pull member in such a manner that in one position (in the analysis mode) the slurry is fed from the sampler to the pump sump and in the other position (in the washing mode), to the drain funnel. In addition, a water supply pipeline having a shut-off valve connects to the pump sump. For washing the sample conveyance system, the pneumatic actuator directing the slurry sample to the drain funnel and the shut-off valve starting water supply to the receiving sump of the pump are actuated simultaneously. Water flowing through the conveying line and other devices of the system in the express laboratory washes them. After the washing is over, the system is switched back to the analysis mode.
However, with such a system, washing of the drain hose and sampling aperture of the sampler is impossible. In practice, it is these elements that are most prone to clogging which is not infrequently the cause of clogging of the drain hose and failure of the system. Gradual accumulation of slurry residue in the drain hose and their subsequent separation from the hose wall results in a substantial contamination of a sample being analyzed. In addition, the conveying line should be completely filled for washing it so that a large amount of water is required, whereas efficiency of washing depends on water velocity thus making it necessary to install a high capacity pump.
Also known in the art is a system for automatic sampling and sample conveyance in sampling slurries (cf. Yu. A. Baranov, System for Automatic Sampling and Slurry Sample Conveyance (in Russian), Jr. Tsvetnaya Metallurgia, No. 20, 1982, pp, 35-37), comprising a sampler having a slurry sampling member in the form of an apertured blade which is mounted at an overfall of a process slurry flow being controlled. The drain of the apertured blade of the sampler is connected by means of a flexible hose to a chamber for accumulation and dispatch of samples through a first check valve. The chamber for accumulation and dispatch of samples is connected, via an electrically controlled valve, to a compressed air supply line, and, via a conveying line, to a sample receiver. In addition, to ensure that the the volume of the sample being dispatched should be always the same, the chamber for accumulation and dispatch of samples is filled with water to the overflow level, water being continuously supplied through a second check valve. During operation of the system, a single sample received by a sampler during one cycle of its operation is fed under gravity through the flexible hose to the chamber for accumulation and dispatch of samples. The accumulated sample is dispatched and conveyed by admitting compressed air to the chamber by actuating the electrically controlled valve. The sample is admitted from the conveying line to the sample receiver and then to a circulation circuit for an X-ray spectral analysis.
The chamber for accumulation and dispatch of samples, conveying line and sample receiver are washed by feeding compressed air, upon actuation of the electrically controlled valve, to the chamber for accumulation and dispatch of samples immediately after it has been filled with water.
This system calls for a large water consumption (more than 150 l/h), yet there is no provision for washing of the sampling aperture and flexible drain hose. It is these parts of the system that are most prone to clogging with slurry thus not only resulting in less reliability of the sample analysis data because the sample is not quite representative, but also causing clogging of the sampler aperture and the hose and up to the complete failure of the system.